Methods of manufacturing semiconductor device

ABSTRACT

Provided is a method of manufacturing a semiconductor device using double patterning. The method includes: forming a first material layer pattern having recesses in a first direction on an object layer and a second material layer pattern formed on the first material layer pattern; selectively etching the second material layer pattern and the first material layer pattern in a direction perpendicular to the first direction to form an etching mask; and etching the object layer to form minute patterns.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims the benefit of Korean Patent Application No.10-2007-0015086, filed on Feb. 13, 2007, in the Korean IntellectualProperty Office, the disclosure of which is incorporated herein in itsentirety by reference.

FIELD OF THE INVENTION

The present invention relates generally to semiconductor devices, andmore particularly, to methods of manufacturing semiconductor devices.

BACKGROUND OF THE INVENTION

As the integration degree of semiconductor devices has increased, thesize and interval (pitch) of patterns constituting circuits has alsobeen reduced. Accordingly, minute patterns should be formed. However, itcan be difficult to form minute patterns that can be applied tosemiconductor devices using, for example, a KrF light source (245 nm) orArF light source (193 nm).

SUMMARY

The present invention provides methods of manufacturing semiconductordevices by double patterning.

According to embodiments of the present invention, a method ofmanufacturing a semiconductor device includes: (a) forming a firstmaterial layer having a first thickness on an objective layer; (b)forming a second material layer having a second thickness on the firstmaterial layer; (c) forming first patterns of a third material layerhaving lines and space patterns on the second material layer; (d)forming first patterns of the second material layer by etching thesecond material layer using the first patterns of the third materiallayer as an etching mask; (e) forming first patterns of the firstmaterial layer by etching the first material layer exposed by theetching mask including the first patterns of the second material layerto have a third thickness that is smaller than the first thickness; (f)forming second patterns of the second material layer having a planarizedtop surface on the first patterns of the first material layer and thefirst patterns of the second material layer, a fourth thickness on thefirst patterns of the second material layer, and a fifth thickness onthe first patterns of the first material layer having the thirdthickness; (g) forming second patterns of the third material layerhaving lines and space patterns in a direction perpendicular to thefirst patterns of the third material layer on the second patterns of thesecond material layer; (h) forming third patterns of the second materiallayer by etching the second patterns of the second material layer andthe first patterns of the second material layer by a first depth that issmaller than the fifth thickness from the top surface of the secondpatterns of the second material layer using the second patterns of thethird material layer as an etching mask; (i) forming second patterns ofthe first material layer by etching the first patterns of the firstmaterial layer that is exposed by the etching mask including the thirdpatterns of the second material layer by the same depth as the firstthickness; and (j) etching the object layer exposed by the etching maskincluding the second patterns of the first material layer.

In step (h), the first depth may be equal to the sum of the fourththickness and the second thickness. The third thickness in step (e) maybe equal to or greater than a minimum thickness of the second patternsof the first material layer that are determined such that the secondpatterns of the first material layer can remain when etching the objectlayer. The object layer, the first material layer, the second materiallayer, and the third material layer may have different etchingselectivities to one another. The first material layer may be formed ofa material that can be removed by an ashing process or a strip process.

The method may further comprise, after step (j), removing the secondpatterns of the first material layer using an ashing process or a stripprocess. The second material layer may be formed of a material that hasan adhesive force with respect to the first material layer and fillrecesses formed in the first material layer. The first material layermay comprise an amorphous carbon layer (ACL). The ACL may be formedusing a coating method or a chemical vapor deposition (CVD) method. Thesecond material layer may comprise SiON. The third material layer maycomprise a photoresist layer.

Step (d) of forming the first patterns of the second material layer orstep (h) of forming the third patterns of the second material layer maycomprise using etching gas containing at least one gas selected from agroup consisting of CF₄, CHF₃, CH₂F₂, and CH₃F. Step (e) of forming thefirst patterns of the first material or step (i) of forming the secondpatterns of the first material layer may comprise using etching gascontaining O₂ gas. Step (j) of etching the object layer may use etchinggas containing at least one gas selected from a group consisting of CF₄,CHF₃, CH₂F₂, C₄F₆, C₅F₈, C₃F₈, and C₂F₆. In step (e), the differencebetween the first thickness and the third thickness may be 1.5 times orgreater the sum of the second thickness and the fourth thickness orgreater. The second material layer may comprise an oxide layer.

According to other embodiments of the present invention, a method ofmanufacturing a semiconductor device includes: (a) forming a firstmaterial layer on an object layer on a semiconductor substrate; (b)forming a second material layer on the first material layer; (c) formingfirst patterns of a third material layer, in which a plurality of firstline patterns are separated in parallel from one another, on the secondmaterial layer; (d) forming first patterns of the second material layerby etching the second material layer using the first patterns of thethird material layer as an etching mask; (e) forming first patterns ofthe first material layer having recesses by etching a portion of thefirst material layer exposed by the etching mask comprising the firstpatterns of the second material layer; (f) forming second patterns ofthe second material layer which fill the recesses and is planarized onthe first patterns of the second material layer; (g) forming secondpatterns of the third material layer formed of second line patterns thatare separated in parallel to one another in a direction perpendicular tothe first line patterns, on the second patterns of the second materiallayer; (h) forming third patterns of the second material layer byetching the first patterns of the second material layer and the secondpatterns of the second material layer until the first patterns of thefirst material layer is exposed for the first time using the secondpatterns of the third material layer as an etching mask; (i) formingsecond patterns of the first material layer by etching the firstpatterns of the first material layer that is exposed by the etching maskcomprising the third patterns of the second material layer until theobject layer is exposed for the first time; and (j) formingsemiconductor patterns by etching the object layer that is exposed bythe etching mask comprising the second patterns of the first materiallayer. The object layer, the first material layer, the second materiallayer, and the third material layer may have different etchingselectivities to one another. The first material layer may be formed ofa material that can be removed by an ashing process or a strip process.

The method may further comprise, after step (j), removing the secondpatterns of the first material layer using an ashing process or a stripprocess. The second material layer may be formed of a material that hasadhesive force with respect to the first material layer and fillrecesses formed in the first material layer. The first material layermay comprise an amorphous carbon layer (ACL). The ACL may be formedusing a coating method or a chemical vapor deposition (CVD) method. Thesecond material layer may comprise SiON. The third material layer maycomprise a photoresist layer. Step (d) of forming the first patterns ofthe second material layer or step (h) of forming the third patterns ofthe second material layer may comprise using etching gas containing atleast one gas selected from a group consisting of CF₄, CHF₃, CH₂F₂, andCH₃F. Step (e) of forming the first patterns of the first material orstep (i) of forming the second patterns of the first material layer maycomprise using etching gas containing O₂ gas. Step (j) of etching theobject layer may use etching gas containing at least one gas selectedfrom a group consisting of CF₄, CHF₃, CH₂F₂, C₄F₆, C₅F₈, C₃F₈, and C₂F₆.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present inventionwill become more apparent by describing in detail exemplary embodimentsthereof with reference to the attached drawings in which:

FIGS. 1A, 2A, 3A, 4A, 5A, 6A, and 7A are plan views of a semiconductordevice illustrating a method of manufacturing the semiconductor deviceaccording to an embodiment of the present invention;

FIG. 1B is a cross-sectional view of the semiconductor device of FIG. 1Ataken along line 1B-1B′ of FIG. 1A;

FIG. 2B is a cross-sectional view of the semiconductor device of FIG. 2Ataken along line 2B-2B′ of FIG. 2A;

FIG. 3B is a cross-sectional view of the semiconductor device of FIG. 3Ataken along line 3B-3B′ of FIG. 3A;

FIG. 4B is a cross-sectional view of the semiconductor device of FIG. 4Ataken along line 4B-4B′ of FIG. 4A;

FIG. 4C is a cross-sectional view of the semiconductor device of FIG. 4Ataken along line 4C-4C′ of FIG. 4A;

FIG. 4D is a cross-sectional view of the semiconductor device of FIG. 4Ataken along line 4D-4D′ of FIG. 4A;

FIG. 4E is a cross-sectional view of the semiconductor device of FIG. 4Ataken along line 4E-4E′ of FIG. 4A;

FIG. 5B is a cross-sectional view of the semiconductor device of FIG. 5Ataken along line 5B-5B′ of FIG. 5A;

FIG. 5C is a cross-sectional view of the semiconductor device of FIG. 5Ataken along line 5C-5C′ of FIG. 5A;

FIG. 5D is a cross-sectional view of the semiconductor device of FIG. 5Ataken along line 5D-5D′ of FIG. 5A;

FIG. 5E is a cross-sectional view of the semiconductor device of FIG. 5Ataken along line 5E-5E′ of FIG. 5A;

FIG. 6B is a cross-sectional view of the semiconductor device of FIG. 6Ataken along line 6B-6B′ of FIG. 6A;

FIG. 6C is a cross-sectional view of the semiconductor device of FIG. 6Ataken along line 6C-6C′ of FIG. 6A;

FIG. 6D is a cross-sectional view of the semiconductor device of FIG. 6Ataken along line 6D-6D′ of FIG. 6A;

FIG. 6E is a cross-sectional view of the semiconductor device of FIG. 6Ataken along line 6E-6E′ of FIG. 6A;

FIG. 7B is a cross-sectional view of the semiconductor device of FIG. 7Ataken along line 7B-7B′ of FIG. 7A;

FIG. 7C is a cross-sectional view of the semiconductor device of FIG. 7Ataken along line 7C-7C′ of FIG. 7A;

FIG. 7D is a cross-sectional view of the semiconductor device of FIG. 7Ataken along line 7D-7D′ of FIG. 7A; and

FIG. 7E is a cross-sectional view of the semiconductor device of FIG. 7Ataken along line 7E-7E′ of FIG. 7A.

DETAILED DESCRIPTION

The invention will be described more fully hereinafter with reference tothe accompanying drawings, in which example embodiments of the inventionare shown. This invention may, however, be embodied in many differentforms and should not be construed as limited to the example embodimentsset forth herein. Rather, the disclosed embodiments are provided so thatthis disclosure will be thorough and complete, and will fully convey thescope of the invention to those skilled in the art. In the drawings, thesize and relative sizes of layers and regions may be exaggerated forclarity. Moreover, each embodiment described and illustrated hereinincludes its complementary conductivity type embodiment as well. Likenumbers refer to like elements throughout.

It will be understood that when an element or layer is referred to asbeing “on”, “connected to” and/or “coupled to” another element or layer,it can be directly on, connected or coupled to the other element orlayer or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directlyconnected to” and/or “directly coupled to” another element or layer,there are no intervening elements or layers present. As used herein, theterm “and/or” may include any and all combinations of one or more of theassociated listed items.

It will be understood that, although the terms first, second, third,etc., may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsmay be used to distinguish one element, component, region, layer and/orsection from another region, layer and/or section. For example, a firstelement, component, region, layer and/or section discussed below couldbe termed a second element, component, region, layer and/or sectionwithout departing from the teachings of the present invention.

Spatially relative terms, such as “below”, “lower”, “above”, “upper” andthe like, may be used herein for ease of description to describe anelement and/or a feature's relationship to another element(s) and/orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90° or atother orientations) and the spatially relative descriptors used hereininterpreted accordingly. Moreover, the term “beneath” indicates arelationship of one layer or region to another layer or region relativeto the substrate, as illustrated in the figures.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular terms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including” when used in thisspecification, specify the presence of stated features, integers, steps,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Example embodiments of the invention are described herein with referenceto plan and cross-section illustrations that are schematic illustrationsof idealized embodiments (and intermediate structures) of the invention.As such, variations from the shapes of the illustrations as a result,for example, of manufacturing techniques and/or tolerances, may beexpected. Thus, the disclosed example embodiments of the inventionshould not be construed as limited to the particular shapes of regionsillustrated herein unless expressly so defined herein, but are toinclude deviations in shapes that result, for example, frommanufacturing. For example, an implanted region illustrated as arectangle will, typically, have rounded or curved features and/or agradient of implant concentration at its edges rather than a binarychange from implanted to non-implanted region. Likewise, a buried regionformed by implantation may result in some implantation in the regionbetween the buried region and the surface through which the implantationtakes place. Thus, the regions illustrated in the figures are schematicin nature and their shapes are not intended to illustrate the actualshape of a region of a device and are not intended to limit the scope ofthe invention, unless expressly so defined herein.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein. Referring toFIGS. 1A and 1B, a method of manufacturing a semiconductor deviceaccording to embodiments of the present invention is illustrated. Afirst material layer 30 having a first thickness T1 is formed on anobject layer 20. The object layer 20 may be formed on a stopper layer10. A second material layer 40 having a second thickness T2 is formed onthe first material layer 30. First patterns 50 of a third material layerhaving a line and space patterns are formed on the second material layer40. The line patterns have a first width W1 and are separated by a thirdwidth W3.

According to an embodiment of the present invention, the object layer 20may include an oxide layer, the first material layer 30 may include anamorphous carbon layer (ACL), the second material layer 40 may includeSiON or oxide layer, and the third material layer may include aphotoresist layer. However, the object layer 20, the first materiallayer 30, the second material layer 40, and the third material layer arenot limited to the above configuration when they are formed of materialshaving different etching selectivity to one another. The second materiallayer 40 may be formed of a material that has an adhesive force to thefirst material layer 30 and that can fill recesses formed in the firstmaterial layer 30. The first material layer 30 including the ACL may beformed by coating or using a chemical vapor deposition (CVD) method.

Referring to FIGS. 2A and 2B, the first patterns of the third materiallayer (50 in FIG. 1B) are used as an etching mask to etch the secondmaterial layer (40 in FIG. 1B) to form a first patterns 40 a of thesecond material layer 40. In this case, when the second material layer40 includes SiON, and the third material layer includes a photoresistlayer, the second material layer 40 is etched using an etching gascontaining at least one selected from the group consisting of CF₄, CHF₃,CH₂F₂, and CH₃F. Meanwhile, when the second material layer 40 is etched,the first patterns 50 of the third material layer are etched to beentirely removed or may partially remain on the first patterns 40 a ofthe second material layer 40. The first material layer 30 that isexposed by an etching mask including the first patterns 40 a of thesecond material layer 40 is partially etched to form first patterns 30 aof the first material layer 30 having recesses 2. In this case, when thefirst material layer 30 includes ACL, and the second material layer 40includes SiON, the first material layer 30 may be etched using anetching gas containing O₂ gas. The first patterns 30 a include a firstregion exposed by the etching mask including the first patterns 40 a ofthe second material layer 40 and a second region that is not exposed bythe etching mask including the first patterns 40 a of the secondmaterial layer 40. That is, the first region is the first patterns 30 aof the first material layer 30 formed below the recesses 2 and has athird thickness T3 and a third width W3. Since recesses 2 need to beformed, the third thickness T3 is smaller than the first thickness T1.

Referring to FIGS. 3A and 3B, second patterns 40 b of the secondmaterial layer 40, which have a planarized top surface on the firstpatterns 30 a of the first material layer 30 and the first patterns 40 aof the second material layer 40, a fourth thickness T4 on the firstpatterns 40 a of the second material layer 40, and a fifth thickness T5on the first patterns 30 a of the first material layer 30 are formed.That is, the second patterns 40 b of the second material layer 40 fillthe recesses 2 and have a planarized top surface on the first patterns40 a of the second material layer 40. As described before, the secondpatterns 40 b of the second material layer 40 have the fifth thicknessT5 in the first region, and the fourth thickness T4 in the secondregion.

Referring to FIG. 4A, second patterns 60 of the third material layerhaving line and space patterns in a vertical direction to the firstpatterns (50 in FIG. 1A) of the third material layer are formed on thesecond patterns 40 b of the second material layer 40. The secondpatterns 60 of the third material layer include line patterns having asecond width W2, which are parallel to and separated from each other bya fourth width W4. Hereinafter, cross-sections of the semiconductordevice in which second patterns 60 of the third material layer areformed will be described.

First, referring to FIG. 4B showing the cross-sectional view taken alongline 4B-4B′ in FIG. 4A, the first patterns 30 a of the first materiallayer 30 have the first thickness T1, the first patterns 40 a of thesecond material layer 40 have the second thickness T2, and the secondpatterns 40 b of the second material layer 40 have the fourth thicknessT4. The second patterns 60 of the third material layer have the secondwidth W2 and are separated from each other by the fourth width W4.

Referring to FIG. 4C showing the cross-sectional view taken along line4C-4C′ of FIG. 4A, the first patterns 30 a of the first material layer30 have the third thickness T3, the first patterns 40 a of the secondmaterial layer 40 are not formed, and the second patterns 40 b of thesecond material layer 40 have the fifth thickness T5. The secondpatterns 60 of the third material layer have the second width W2 and areseparated from each other by the fourth width W4.

Referring to FIG. 4D showing the cross-sectional view taken along line4D-4D′ of FIG. 4A, the first patterns 30 a of the first material layer30 have the first thickness T1 in the second region where the firstpatterns 40 a of the second material layer 40 are formed and the thirdthickness T3 in the first region where the first patterns 40 a of thesecond material layer 40 are not formed. The first region has the thirdwidth W3 and the second region has the first width W1. The secondpatterns 40 b of the second material layer 40, which fill the recesses 2formed in the first patterns 30 a of the first material layer 30 andhave a planarized top surface on the first patterns 40 a of the secondmaterial layer 40, have the fifth thickness T5 in the first region andthe fourth thickness T4 in the second region. Second patterns 60 of thethird material layer are formed on the second patterns 40 b of thesecond material layer 40.

Referring to FIG. 4E showing the cross-sectional view taken along line4E-4E′ of FIG. 4A, the first patterns 30 a of the first material layer30 have the first thickness T1 in the second region where the firstpatterns 40 a of the second material layer 40 are formed and the thirdthickness T3 where the first patterns 40 a of the second material layer40 are not formed. The first region has the third width W3 and thesecond region has the first width W1. The second patterns 40 b of thesecond material layer 40, which fill the recesses 2 formed in the firstpatterns 30 a of the first material layer 30 and have a planarized topsurface on the first patterns 40 a of the second material layer 40, havethe fifth thickness T5 in the first region and the fourth thickness T4in the second region. Second patterns 60 of the third material layer arenot formed on the second patterns 40 b of the second material layer 40.The difference between the first thickness T1 and the third thickness T3may be 1.5 times or greater the sum of the second thickness T2 and thefourth thickness T4 (i.e., T1−T3≧1.5(T2+T4)) in order to secure thirdpatterns (40 c in FIG. 6E) of the second material layer 40 that areformed as an etching mask on the second patterns (30 b in FIG. 6E) ofthe first material layer 30 having the third width in subsequentprocesses.

Referring to FIG. 5A, the second patterns 60 of the third material layerare used as an etching mask to etch the second patterns 40 b of thesecond material layer 40 and the first patterns 40 a of the secondmaterial layer 40 from the top surface of the second patterns 40 b ofthe second material layer 40 to a first depth H1 to form third patterns40 c and 40 d of the second material layer 40. In this case, when thesecond material layer 40 includes SiON and the third material layerincludes a photoresist layer, the second material layer 40 is etchedusing an etching gas containing at least one selected from the groupconsisting of CF₄, CHF₃, CH₂F₂, and CH₃F. Meanwhile, when the secondmaterial layer 40 is etched, the second patterns 60 of the thirdmaterial layer are all etched to be entirely removed or may partiallyremain on the third patterns 40 c and 40 d of the second material layer40. When the second patterns 30 of the third material layer are alletched and entirely removed, the second patterns 40 b of the secondmaterial layer 40 are all etched and thus only the first patterns 40 aof the second material layer 40 remains to form the third patterns 40 dof the second material layer 40. Hereinafter, cross-sections of thesemiconductor device in which the third patterns 40 c and 40 d of thesecond material layer will be described.

Referring to FIGS. 4B and 5B, the cross-sectional view taken along lines5B-5B′ of FIG. 5A shows the second patterns 60 of the third materiallayer are used as an etching mask to etch the second patterns 40 b ofthe second material layer 40 and the first patterns 40 a of the secondmaterial layer 40 from a top surface of the second patterns 40 b of thesecond material layer 40 to the first depth H1 to form third patterns 40c and 40 d of the second material layer 40. The first depth H1 may beequal to the sum of the fourth thickness T4 and the second thickness T2.

Referring to FIGS. 4C and 5C, the second patterns 40 b of the secondmaterial layer 40 are etched using the second patterns 60 of the thirdmaterial layer as an etching mask, as illustrated in the cross-sectionalview taken along line 5C-5C′ of FIG. 5A, from a top surface of thesecond patterns 40 b of the second material layer 40 to the first depthH1 to form the third patterns 40 c of the second material layer 40. Thefirst depth H1 may be smaller than the fifth thickness T5.

Referring to FIGS. 4D and 5D, the cross-sectional view taken along line5D-5D′ of FIG. 5A shows the second patterns 60 of the third materiallayer are used as an etching mask to etch the second material layer 40,and thus the third patterns 40 c and 40 d of the second material layer40 are not etched.

Referring to FIGS. 4E and 5E, the cross-sectional view taken along aline 5E-5E′ of FIG. 5A shows the second patterns 60 of the thirdmaterial layer are used as an etching mask to etch the second patterns40 b of the second material layer 40 and the first patterns 40 a of thesecond material layer 40 to a depth equal to the sum of the fourththickness T4 and the second thickness T2 to form the third patterns 40 cof the second material layer. In other words, in the first region havingthe third width W3, the third patterns 40 c of the second material layer40 remaining only to a sixth thickness is formed, and the first patterns40 a of the first material layer 30 having the third thickness areformed. Meanwhile, in the second region having the first width W1, thefirst patterns 40 a of the second material layer 40 and the secondpatterns 40 b of the second material layer 40 are all etched to beremoved, and the first patterns 30 a of the first material layer 30having the first thickness is formed.

According to an embodiment of the present invention, the second patterns40 b of the second material layer 40 and the first patterns 40 a of thesecond material layer 40 are etched to the first depth that is equal tothe sum of the fourth thickness T4 and the second thickness T2 from atop surface of the second patterns 40 b of the second material layer 40using the second patterns 60 of the third material layer as an etchingmask to form third patterns 40 c and 40 d of the second material layer40. Meanwhile, the second patterns 40 b of the second material layer 40and the first patterns 40 a of the second material layer 40 are etcheduntil the first patterns 30 a of the first material layer 30 are exposedfor the first time using the second patterns 60 of the third materiallayer as an etching mask to form third patterns 40 c and 40 d of thesecond material layer 40. When the second patterns 40 b of the secondmaterial layer 40 and the first patterns 40 a of the second materiallayer 40 are etched until the first patterns 30 a of the first materiallayer 30 are exposed for the first time, the first patterns 30 a of thefirst material layer 30 is exposed in the cross-sections illustrated inFIGS. 5B and 5E, but is not exposed in the cross-sections illustrated inFIGS. 5C and 5D.

Referring to FIG. 6A, the first patterns 30 a of the first materiallayer 30 exposed by the etching mask including the third patterns 30 bof the second material layer 40 are etched to the depth equal to thefirst thickness T1 to form the second patterns 30 b of the firstmaterial layer 30. In this case, when the first material layer 30includes ACL and the second material layer 40 includes SiON, the firstmaterial layer 30 can be etched using an etching gas containing O₂ gas.The third patterns 40 c and 40 d of the second material layer 40 used asan etching mask while the first material 30 are etched, are all etchedto be entirely removed or may partially remain on the second patterns 30b of the first material layer 30. Hereinafter, cross-sections of thesemiconductor device in which the second patterns 30 b of the firstmaterial layer 30 will be described.

First, referring to FIGS. 5B and 6B showing the cross-sectional viewtaken along line 6B-6B′ of FIG. 6A, the first patterns 30 a of the firstmaterial layer 30 exposed by the etching mask including the thirdpatterns 40 c and 40 d of the second material layer 40 are etched to thedepth equal to the first thickness T1 to form the second patterns 30 bof the first material layer 30 and the object layer 20 is exposed to thefourth width W4.

Referring to FIGS. 5C and 6C showing the cross-sectional view takenalong a line 6C-6C′ of FIG. 6A, since the first material layer 30exposed by the etching mask including the third patterns 40 c of thesecond material layer 40 is not present, the first patterns 30 a of thefirst material layer 30 having the third thickness T3 is not etched.

Referring to FIGS. 5D and 6D showing the cross-sectional view takenalong a line 6D-6D′ of FIG. 6A, since the first material layer 30exposed by the etching mask including the third patterns 40 c of thesecond material layer 40 is not present, the first patterns 30 a of thefirst material layer 30 having the third thickness T3 and the firstthickness T1 is not etched.

Referring to FIGS. 5E and 6E showing the cross-sectional view takenalong a line 6E-6E′ of FIG. 6A, the first patterns 30 a of the firstmaterial layer 30 exposed by the etching mask including the thirdpatterns 40 c of the second material layer 40 having the first width W1are etched by the first thickness T1. The first patterns of the firstmaterial layer that are not exposed by the etching mask including thethird patterns 40 c of the second material layer 40 have a third widthW3 and a third thickness T3 and is not etched.

According to an embodiment of the present invention, the first patterns30 a of the first material layer 30 exposed by the etching maskincluding the third patterns 40 c and 40 d of the second material layer40 is etched to the depth equal to the first thickness T1 to form thesecond patterns 30 b of the first material layer 30. Meanwhile,according to another embodiment of the present invention, the firstpatterns 30 a of the first material layer 30 exposed by the etching maskincluding the third patterns 40 c and 40 d of the second material layer40 are etched until the object layer 20 is exposed for the first time toform the second patterns 30 b of the first material layer 30. When thefirst patterns 30 a of the first material layer 30 are etched until theobject layer 20 is etched for the first time, the object layer 20 isexposed in the cross-sections illustrated in FIGS. 6B and 6E, but is notexposed in the cross-sections illustrated in FIGS. 6C and 6D.

Referring to FIG. 7A, the object layer 20 exposed by the etching maskincluding the second patterns 30 b of the first material layer 30 isetched to form the first patterns 20 a of the object layer 20. A stopperlayer 10 is formed below the object layer 20 to control the etchingdepth. Contact holes can be formed in the region where the stopper layer10 is exposed by the etched object layer 20, and the region has thefirst width W1 and the fourth width W4 that form the sides of arectangle. Hereinafter, cross-sections of the semiconductor device inwhich the first patterns 20 a of the object layer 20 are formed will bedescribed.

Referring to FIGS. 6B and 7B showing the cross-sectional view takenalong line 7B-7B′ of FIG. 7A, the object layer 20 exposed by the etchingmask including the second patterns 30 b of the first material layer 30is etched to form the first patterns 20 a of the object layer 20. Thefirst patterns 20 a of the object layer 20 have the second width W2 andare separated from each other to the fourth width W4.

Referring to FIGS. 6C and 7C showing the cross-sectional view takenalong line 7C-7C′ of FIG. 7A, since the object layer exposed by theetching mask including the second patterns 30 b of the first materiallayer 30 is not present, the first patterns 20 a of the object layer isnot etched.

Referring to FIGS. 6D and 7D showing the cross-sectional view takenalong line 7D-7D′ of FIG. 7A, since the object layer exposed by theetching mask including the second patterns 30 b of the first materiallayer 30 is not present, the first patterns 20 a of the object layer isnot etched.

Referring to FIGS. 6E and 7E showing the cross-sectional view takenalong line 7E-7E′ of FIG. 7A, the object layer exposed by the etchingmask including the second patterns 30 b of the first material layer 30having the first width W1 are etched by a seventh width T7. Meanwhile,the object layer that is not exposed by the etching mask including thesecond patterns 30 b of the first material layer 30 forms the firstpatterns 20 a of the object layer having the third width W3 and theseventh thickness T7. Meanwhile, the third thickness T3 may be a minimumthickness or greater at which the second patterns 30 b of the firstmaterial can remain while the object layer 20 is etched to apredetermined depth, for example, the seventh thickness T7 in order toexclude the possibility that the object layer below the second patterns30 b of the first material layer 30 be partially etched. Also, the firstmaterial layer 30 may be preferably formed of a material that can beremoved using an ashing process or strip process. In particular, whenthe first material layer 30 includes ACL, the first material layer 30can be easily removed using an O₂ ashing process or strip process. Afterthe object layer 20 is removed, the second patterns 30 b of the firstmaterial layer 30 that may remain on the first patterns 20 a of theobject layer can be removed using an ashing process or a strip process.

According to the method of manufacturing a semiconductor device of thepresent invention, minute patterns can be formed by double patterning.

While the present invention has been particularly shown and describedwith reference to exemplary embodiments thereof, the exemplaryembodiments should be considered in descriptive sense only and not forpurposes of limitation. For example, it will be understood by thoseskilled in the art that although the present invention relates tomethods of manufacturing semiconductor devices in which contact holesare formed, the present invention is not limited thereto, and may alsobe applied to methods of forming gate patterns, capacitor patterns,and/or wire patterns, etc.

1. A method of manufacturing a semiconductor device, the methodcomprising: (a) forming a first material layer having a first thicknesson an object layer; (b) forming a second material layer having a secondthickness on the first material layer; (c) forming first patterns of athird material layer having lines and space patterns on the secondmaterial layer; (d) forming first patterns of the second material layerby etching the second material layer using the first patterns of thethird material layer as an etching mask; (e) forming first patterns ofthe first material layer by etching the first material layer exposed bythe etching mask including the first patterns of the second materiallayer to have a third thickness that is smaller than the firstthickness; (f) forming second patterns of the second material layerhaving a planarized top surface on the first patterns of the firstmaterial layer and the first patterns of the second material layer, afourth thickness on the first patterns of the second material layer, anda fifth thickness on the first patterns of the first material layerhaving the third thickness; (g) forming second patterns of the thirdmaterial layer having lines and space patterns in a directionperpendicular to the first patterns of the third material layer on thesecond patterns of the second material layer; (h) forming third patternsof the second material layer by etching the second patterns of thesecond material layer and the first patterns of the second materiallayer by a first depth that is smaller than the fifth thickness from thetop surface of the second patterns of the second material layer usingthe second patterns of the third material layer as an etching mask; (i)forming second patterns of the first material layer by etching the firstpatterns of the first material layer that is exposed by the etching maskincluding the third patterns of the second material layer by the samedepth as the first thickness; and (j) etching the object layer exposedby the etching mask including the second patterns of the first materiallayer.
 2. The method of claim 1, wherein in step (h), the first depth isequal to the sum of the fourth thickness and the second thickness. 3.The method of claim 1, wherein the third thickness in step (e) is equalto or greater than a minimum thickness of the second patterns of thefirst material layer that are determined such that the second patternsof the first material layer can remain when etching the object layer. 4.The method of claim 1, wherein the object layer, the first materiallayer, the second material layer, and the third material layer havedifferent etching selectivities relative to one another.
 5. The methodof claim 1, wherein the first material layer is formed of a materialthat can be removed by an ashing process or a strip process.
 6. Themethod of claim 5, further comprising, after step (j), removing thesecond patterns of the first material layer using an ashing process or astrip process.
 7. The method of claim 1, wherein the second materiallayer is formed of a material that has an adhesive force with respect tothe first material layer and fill recesses formed in the first materiallayer.
 8. The method of claim 1, wherein the first material layercomprises an amorphous carbon layer (ACL).
 9. The method of claim 8,wherein the ACL is formed using a coating method or a chemical vapordeposition (CVD) method.
 10. The method of claim 8, wherein the secondmaterial layer comprises SiON.
 11. The method of claim 10, wherein thethird material layer comprises a photoresist layer.
 12. The method ofclaim 11, wherein step (d) of forming the first patterns of the secondmaterial layer or step (h) of forming the third patterns of the secondmaterial layer comprises using etching gas containing at least one gasselected from a group consisting of CF₄, CHF₃, CH₂F₂, and CH₃F.
 13. Themethod of claim 11, wherein step (e) of forming the first patterns ofthe first material or step (i) of forming the second patterns of thefirst material layer comprises using etching gas containing O₂ gas. 14.The method of claim 11, wherein step (j) of etching the object layerusing etching gas containing at least one gas selected from a groupconsisting of CF₄, CHF₃, CH₂F₂, C₄F₆, C₅F₈, C₃F₈, and C₂F₆.
 15. Themethod of claim 10, wherein in step (e), the difference between thefirst thickness and the third thickness is 1.5 times or greater the sumof the second thickness and the fourth thickness.
 16. The method ofclaim 8, wherein the second material layer comprises an oxide layer. 17.A method of manufacturing a semiconductor device, the method comprising:(a) forming a first material layer on an object layer on a semiconductorsubstrate; (b) forming a second material layer on the first materiallayer; (c) forming first patterns of a third material layer, in which aplurality of first line patterns are separated in parallel from oneanother, on the second material layer; (d) forming first patterns of thesecond material layer by etching the second material layer using thefirst patterns of the third material layer as an etching mask; (e)forming first patterns of the first material layer having recesses byetching a portion of the first material layer exposed by the etchingmask comprising the first patterns of the second material layer; (f)forming second patterns of the second material layer which fill therecesses and is planarized on the first patterns of the second materiallayer; (g) forming second patterns of the third material layer formed ofsecond line patterns that are separated in parallel to one another in adirection perpendicular to the first line patterns, on the secondpatterns of the second material layer; (h) forming third patterns of thesecond material layer by etching the first patterns of the secondmaterial layer and the second patterns of the second material layeruntil the first patterns of the first material layer is exposed usingthe second patterns of the third material layer as an etching mask; (i)forming second patterns of the first material layer by etching the firstpatterns of the first material layer that is exposed by the etching maskcomprising the third patterns of the second material layer until theobject layer is exposed; and (j) forming semiconductor patterns byetching the object layer that is exposed by the etching mask comprisingthe second patterns of the first material layer.
 18. The method of claim17, wherein the object layer, the first material layer, the secondmaterial layer, and the third material layer have different etchingselectivities to one another.
 19. The method of claim 17, wherein thefirst material layer is formed of a material that can be removed by anashing process or a strip process.
 20. The method of claim 19, furthercomprising, after step (j), removing the second patterns of the firstmaterial layer using an ashing process or a strip process.
 21. Themethod of claim 17, wherein the second material layer is formed of amaterial that has adhesive force with respect to the first materiallayer and fill recesses formed in the first material layer.
 22. Themethod of claim 17, wherein the first material layer comprises anamorphous carbon layer (ACL).
 23. The method of claim 22, wherein theACL is formed using a coating method or a chemical vapor deposition(CVD) method.
 24. The method of claim 22, wherein the second materiallayer comprises SiON.
 25. The method of claim 24, wherein the thirdmaterial layer comprises a photoresist layer.
 26. The method of claim25, wherein step (d) of forming the first patterns of the secondmaterial layer or step (h) of forming the third patterns of the secondmaterial layer comprises using etching gas containing at least one gasselected from a group consisting of CF₄, CHF₃, CH₂F₂, and CH₃F.
 27. Themethod of claim 25, wherein step (e) of forming the first patterns ofthe first material or step (i) of forming the second patterns of thefirst material layer comprises using etching gas containing O₂ gas. 28.The method of claim 25, wherein step (j) of etching the object layerusing etching gas containing at least one gas selected from a groupconsisting of CF₄, CHF₃, CH₂F₂, C₄F₆, C₅F₈, C₃F₈, and C₂F₆.
 29. Themethod of claim 22, wherein the second material layer comprises an oxidelayer.
 30. The method of claim 17, wherein in step (c), the first linepatterns having a first width are separated in parallel to one anotherby a third width, and in step (g), the second line patterns having asecond width are separated in parallel to one another by a fourth width,and in step (j), the semiconductor patterns are contact hole patternshaving the first width and the fourth width as sides of a rectangle.